How old is she again?

So lately i've been spending quite some time with this crabby 11 - year old nice of mine. her name is Flynn and she's my first niece. The thing about her is you can almost forget that your talking to an elementary kid because she talks and behaves older than her age. It's like there's no age gap between you. I don't know if  i just really behave like a kid or she behaves like an adult but somehow we met in between. 

Last night we agreed to watch an episode of House of Anubis but her grandma forbid her so we sneaked into their living room jut to complete that pledge. But then they realized that someone was there. So we ran to each other's room and locked our doors laughing. Am i corrupting her?